Pinealectomy Does Not Modulate the Characteristics of 24-h Variation in Air-Gulping Activity of Clarias batrachus

The effect of pinealectomy on the characteristics of circadian variation in air-gulping activity of Clarias batrachus was examined. Live Clarias batrachus of mixed sex (40–50 gm body weight) were procured from the local market and kept in the stock aquaria under the laboratory conditions for proper acclimation. Following 7 days of acclimation, animals were randomly selected from the stock aquaria and divided into two groups. The pineal was surgically removed from fishes in the first group (P×G) and the second group was left intact (IG). The individuals were kept in the specially designed glass aquaria. They were exposed under LD 12:12 (Lights on at 06:00) inside the chronocubicles for recording of the air-gulping activity. Results clearly indicate that the air-gulping activity exhibits a significant 24 h rhythm in both Intact (IG) and Pinealectomized (P×G) groups of this catfish. The peak of the air-gulping activity rhythm was located in the dark phase of the LD cycle in both groups. It may be concluded that pinealectomy does not modulate the 24 h rhythm in air-gulping activity of Clarias batrachus under LD 12:12.     

Juvenile hormone-dependent motor activation in the adult locust <Emphasis Type="Italic">Locusta migratoria</Emphasis>

Abdominal motoneurones of the locust Locusta migratoria were investigated in immature, mature and allatectomised females to compare their response characteristics during reproductive development. These motoneurones were chosen because they control muscles which are involved in extreme lengthening during egg-laying behaviour. The study focused on changes in motoneurone firing activity and its possible regulation by juvenile hormone. In isolated nerve-muscle preparations, increased resting motor activity was found in mature (>14 days) but not in immature females (<5 days). Removing the corpora allata, the gland producing juvenile hormone in insects, prevented increased motor activity. Stimulus evoked activation of the motor system led to a characteristic burst of action potentials which lasted for a few seconds. The time-course and amount of activation changed significantly during reproductive development. Mature females displayed longer lasting and higher activity than immature or allatectomised females, but only those segments involved in egg-laying were found to express the altered firing properties. Single cell analysis of motoneurone dendritic morphology or membrane properties revealed no evidence that could be causative for the activity changes seen during reproductive development. The results suggest that altered motoneurone activity serves to adapt females to the neuromuscular requirements of egg-laying behaviour.     

Effect of Pinealectomy on Re-entrainment of Air-gulping Activity in Indian Walking Catfish,Clarias batrachus

The present study was aimed to examine the effect of pinealectomy on re-entrainment of air-gulping activity in Indian walking catfish Clarias batrachus under various LD phases. Live Clarias batrachus of mixed sex (40-50g body weight) were procured from the local market and kept in the stock aquaria under the laboratory conditions for proper acclimation. Following 7 days of acclimation, animals were randomly selected from the stock aquaria and divided into 2 groups. The pineal was surgically removed from one group (P_xG) and the other group was treated as intact control group (IG). Both groups were exposed under LD 12:12 cycle inside the chronocubicles. In every 7 days LD schedule was delayed by 4 hours by lengthening of the light-on time. Both intact and pinealectomized animals are exhibited 24h rhythm in air-gulping behaviour and its entrainability irrespective of phase shifts of LD cycle. However, the phase angle of peak with reference to light on hour gradually decreased from phase 1 to phase 4, irrespective of treatment (intact/pinealectomized). Further, it has been noticed that the occurrence of multifrequency rhythm (24h, 12h and 6h) is being decreased from phase 1 to phase 4. It could be concluded that daily light-dark cycle plays an important role in modulating the rhythmic characteristics of air-breathing activity in Clarias batrachus and that pinealectomy does not modulate the effects of LD cycles on such activity.     

Trends in breeding phenology across ten decades show varying adjustments to environmental changes in four wader species

Capsule: During 1928–2016, initiation of egg-laying advanced in two wader species, remained unchanged in one, and was delayed in one species. The changes across years and variation among species can be explained by climatic variables and differences in migratory strategies.

Aims: To document possible changes in initiation of egg-laying in common Danish wader species since the early part of the 20th century and seek possible correlations between egg-laying, timing of arrival and environmental factors.

Methods: Annual records of the first eggs and chicks found on the scientific reserve of Tipperne in western Denmark 1928–2016 were analysed using linear regression to determine patterns in timing of egg-laying, pre-breeding length and influence of climate factors.

Results: Two short/medium-distance migrant wader species, Northern Lapwing Vanellus vanellus and Common Redshank Tringa totanus advanced breeding initiation by about one week, with winter North Atlantic oscillation Index and spring temperature as important predictors. By contrast, two long-distance migrants, Black-tailed Godwit Limosa limosa and Ruff Calidris pugnax, did not advance egg-laying, and Ruff actually delaying it. As a result, the pre-laying period was significantly prolonged in both Black-tailed Godwit (21 days) and Ruff (52 days), while there was no significant change for Common Redshank.

Conclusion: Long-distance migrants are able to adjust spring arrival but unlike short/medium-distance migrants, do not necessarily adjust breeding initiation.     

Control of the moldsAspergillus sydowi andPenicillium citrinum in laboratory colonies of the lone-star tick,Amblyomma americanum (Acari: Ixodidae)

Contamination of tick colonies by molds is a widespread problem. Ticks held in moldy containers have a consistently higher mortality rate compared with containers having little or no mold growth. Three fungicides (captan, folpet, benlate), a wetting agent (Triton X-100), and chlorine gas (from 0.052% aqueous sodium hypochlorite) were evaluated for activity against the moldsAspergillus sydowi andPenicillium citrinum in laboratory colonies of the lone star tick,Amblyomma americanum (L.). Only chlorine gas caused a significant reduction in mold growth in paper containers used to hold ticks, without harming them. Significantly more adults were alive at 180 days post-treatment in aquaria with chlorine gas than in chlorine-gas-free aquaria, whereas mortality in nymphs under these conditions was unchanged. Eggs oviposited in aquaria treated with chlorine gas failed to hatch.     

Hormonal control of egg-laying in the marine pulmonate,Onchidium verruculatum

Extirpation of the pleurovisceral ganglia (PV) blocked egg-laying whereas reimplantation of PV or injection of a PV homogenate into PV-less animals restored the egg-laying capacity of the marine pulomonate, O. verruculatum. Injection of PV homogenate induced egg-laying in intact, mature individuals within 15–45 minutes. Boiling of the homogenate for 15 minutes did not abolish its egg-laying efficacy. However, after incubation with trypsin, a PV homogenate lost its potency. Homogenates of PV from colchicinized animals could not induce egg-laying in intact Onchidium. Similarly, colchicinized animals did not respond to a PV ectract from intact Onchidium. It is hypothesized that egg-laying in O. verruculatum is under the control of a heat-stable, trypsin sensitive hormone secreted by the PV ganglia.     

Multiple cryotherapy applications attenuate oxidative stress following skeletal muscle injury

Objectives: To investigate the effects of multiple cryotherapy applications after muscle injury on markers of oxidative stress.

Methods: Following cryolesion-induced skeletal muscle injury in rats, ice was applied at the injured site for 30?minutes, three times per day, on the day of injury, and for 2 days after injury. To determine the effect of the cryotherapy treatment on markers of oxidative stress, biochemical analyses were performed 3, 7, and 14 days after injury.

Results: Compared with non-treated animals, cryotherapy reduced dichlorofluorescein at 7 and 14 days post-injury and thiobarbituric acid reactive substances levels at 3 and 7 days post-injury (P?P?>?0.05), whereas non-treated groups demonstrated lower levels than the control group (P?P?P?=?0.92).

Discussion: Cryotherapy reduced the production of reactive oxygen species after muscle injury, resulting in an attenuated response of the antioxidant system. These findings suggest that using multiple cryotherapy applications is efficient to reduce oxidative stress.     

Biosurfactant-enhanced degradation of residual hydrocarbons from ship bilge wastes

The use of Bacillus subtilis O9 biosurfactant (surfactin) and of bioaugmentation to improve the treatment of residual hydrocarbons from ship bilge wastes was studied. A biodegradation experiment was conducted in aquaria placed outdoors under non-aseptic conditions. Three treatments were examined: culture medium plus bilge wastes, bioaugmentation with microorganisms from bilge wastes, and bioaugmentation plus biosurfactant. Samples were analyzed for viable counts, aliphatic and aromatic hydrocarbon concentrations, n-C17/pristane and n-C18/phytane ratios. While the addition of biosurfactant stimulated hydrocarbon degradation, bioaugmentation did not produce any remarkable effect. At day 10, the remaining percentages of aliphatic and aromatic hydrocarbons in aquaria, which received biosurfactant, were 6.8 and 7.2, respectively, while it took 20 days to reach comparable results with the other treatments. The biosurfactant did not affect the preferential biodegradation of n-C17/pristane and n-C18/phytane. This biosurfactant, which can be produced in a relatively simple and inexpensive process, is a promising alternative in the optimization of hydrocarbon waste treatment. Journal of Industrial Microbiology & Biotechnology (2000) 25, 70–73. Received 26 January 2000/ Accepted in revised form 09 June 2000     

BREEDING BIOLOGY AND BEHAVIOUR OF THE QUAIL FINCH ORTYGOSPIZA ATRICOLUS

Summary

Nuttall, R.J. 1992. Breeding biology and behaviour of the Quail Finch Ortygospiza atricollis. Ostrich 63:110-117.

During a study of the breeding biology of the Quail Finch Ortygospiza atricollis, observations of nest-building, egg-laying, incubation and nestling periods, and nestling development in a grassland near Pietermaritzburg, South Africa were supplemented with observations of breeding behaviour in captivity. Mean clutch size was 4,5 and eggs were laid at intervals of approximately one day. Incubation began after the third or fourth egg was laid. An incubation period of 15–16 days and an estimated nestling period of 18–19 days was recorded. Incubation and brooding are shared by both sexes. Breeding success was low (26,7% ?28,6%), with most losses resulting from predation during either the egg-laying or incubation stages.     

Egg-laying rhythm in <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>

Extensive research has been carried out to understand how circadian clocks regulate various physiological processes in organisms. The discovery of clock genes and the molecular clockwork has helped researchers to understand the possible role of these genes in regulating various metabolic processes. In Drosophila melanogaster, many studies have shown that the basic architecture of circadian clocks is multi-oscillatory. In nature, different neuronal subgroups in the brain of D. melanogaster have been demonstrated to control different circadian behavioural rhythms or different aspects of the same circadian rhythm. Among the circadian phenomena that have been studied so far in Drosophila, the egg-laying rhythm is unique, and relatively less explored. Unlike most other circadian rhythms, the egg-laying rhythm is rhythmic under constant light conditions, and the endogenous or free-running period of the rhythm is greater than those of most other rhythms. Although the clock genes and neurons required for the persistence of adult emergence and activity/rest rhythms have been studied extensively, those underlying the circadian egg-laying rhythm still remain largely unknown. In this review, we discuss our current understanding of the circadian egg-laying rhythm in D. melanogaster, and the possible molecular and physiological mechanisms that control the rhythmic output of the egg-laying process.     

Circadian rhythm in locomotor activity in the burrower crayfish Procambarus acanthophorus (Villalobos 1948)

Crayfish Procambarus acanthophorus is a burrower that spends long periods building deep tunnels to reach the water table during the dry season; thus, its survival entertains a close ecological relationship with the sediment. The aim of this work was to determine whether the properties of the circadian rhythm of locomotor activity could be modified by the sediment availability. Experiments were conducted in both aquaria filled with sediment or filled with water, under cycles of Bright and Dim Illumination (BI:DI, 12:12 h) or under continuous DI:DI. The rhythm of locomotor activity was entrained with the photoperiod in aquaria with sediment or water; however, statistical differences between conditions were obtained comparing the period and the level of activity under free-running. These data suggest that the substrate’s sensorial perception could be encoded as a significant ecological parameter that exerts influence in the physiological mechanisms that control the temporal order in P. acanthophorus.     

环链虫草Cordyceps cateniannulata对番茄生长和抗氧化酶活性的影响

【目的】评估环链虫草Cordyceps cateniannulata对植物促生和植物抗氧化酶活性的影响。【方法】本研究利用浸种法将环链虫草接种于番茄植物体,在接种后的第30天和60天,通过番茄株高、根长、地上和地下部分的干鲜重指标评价其对番茄生长的影响;在接种后第10、20、30、60和90天,通过选择性培养基分析其在番茄不同组织中的生存情况,使用形态学及DNA序列比对的方法检验所分离菌株与原有菌株的一致性。在处理后的第30天,检测番茄叶片中的过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)及丙二醛(MDA)含量,观察环链虫草对番茄的抗氧化酶活性影响。【结果】环链虫草可定殖于番茄幼苗且对番茄生长有显著促进作用,菌株对植株的定殖偏好性分别为根部>茎部>叶部。酶活检测结果表明,处理组番茄叶片防御酶活性均呈显著升高的趋势,其中POD、CAT、SOD活性分别比对照增加了52.21%、75.31%和158.59%,MDA含量下降了35.15%。【结论】环链虫草可以通过浸种的方法感染并定殖番茄幼苗的根、茎、叶,促进番茄幼苗的生长并提高番茄抗氧化酶活性,具有较好的田间...     

A preliminary investigation into the use of the invasive golden apple snail,Pomacea canaliculata (Lamarck, 1822), as a water purifier and food source in the breeding ponds of the oriental weatherloach Misgurnus anguillicaudatus (Cantor, 1842)

This study investigated the feasibility of using an invasive snail, Pomacea canaliculata, as a food source and water purifier for the commercial breeding of the loach Misgurnus anguillicaudatus. The predatory potential of M. anguillicaudatus (3.5–5.5?g) against hatchling snails was evaluated in aquaria and simulated paddy fields. Some hatchling snails left the water to avoid being preyed upon by the loaches, and approximately 10 hatchlings died per day in the presence of five loaches in aquaria, whereas a weaker snail control effect was observed in the simulated paddy fields. The growth of rice seedlings (Oryza sativa) was not reduced by the presence of hatchling snails alone, but the shoot biomass of seedlings coexisting with snails was promoted after introducing the loaches. Additionally, the presence of P. canaliculata adults improved the aquatic environment in the short term for loach breeding by decreasing the turbidity of the water. Importantly, M. anguillicaudatus (12–18?g) mortality decreased and its weight increased in the presence of adult snails.     

鼠衣原体改善DSS诱导的小鼠溃疡性结肠炎的作用研究

【目的】探讨鼠衣原体(Chlamydia muridarum)对小鼠溃疡性结肠炎的作用。【方法】取15只雌性C57BL/6J小鼠随机分为3组,每组5只动物,分别为空白对照组(Control)、肠炎模型组(DSS)、实验组(CM+DSS)。选取CM+DSS组小鼠予以2×10⁵ IFU的鼠衣原体灌胃处理,并在其感染后第29天开始,给予DSS组和CM+DSS组的小鼠2%DSS饮水,持续5d,每天监测小鼠体重和肠炎疾病评分,实验结束后检测小鼠结肠长度和结肠组织炎性改变。【结果】肠炎模型组的小鼠均表现出典型的肠炎症状(包括体重减轻、肠炎疾病评分、结肠长度和组织炎性改变);而经鼠衣原体预处理的小鼠(CM+DSS组)肠炎症状显著减轻,表现在肠炎疾病评分降低,体重和结肠长度有所恢复,肠组织炎性损伤减轻。【结论】鼠衣原体对DSS诱导的小鼠溃疡性结肠炎具有改善作用。     

Ecdysteroids in females and eggs of the Ixodid tick Amblyomma hebraeum

Summary

A mated Amblyomma hebraeum female will engorge on a host for about 8 days before detaching and beginning the maturation of its single egg batch which is laid during a period of about 30 days. The feeding period is characterized by an important synthesis of endocuticular material occurring before the rapid feeding phase. This latter phase, correlated with an enormous weight uptake, shows an increase of ecdysteroid levels measured in the whole animal by RIA. However, the hemolymphatic levels of ecdysteroids remain very low (12 pg 20-hydroxyecdysone equivalent (20-OH-E eq.) per μ1. Within 4 days after detachment, the salivary glands degenerate. Ecdysteroid levels in the whole animal continue to increase, reaching high values (about 500 ng 20-OH-E eq./tick) at the moment of oviposition which begins 10–14 days after dropping. During the same period, hemolymphatic ecdysteroid levels increase, rising to a peak (600 pg 20-OH-E eq./μ1) 1 day prior to the beginning of oviposition. Then, the levels decrease and stabilize around 250 pg 20-OH-E eq./μl during egg-laying. Freshly laid eggs contain large amounts of ecdysteroids (2744 pg 20-OH-E eq./mg).

20-Hydroxyecdysone and ecdysone have been found to be the major free ecdysteroids in hemolymph, ovaries and eggs (verified by the HPLC-RIA technique and GC-MF of silylated HPLC fractions). Helix juice (or esterase) labile ecdysteroid conjugates do not seem to be present to any noticeable extent in hemolymph, ovaries and eggs.     

The role of the osphradium in chemoreception by the snail Biomphalaria glabrata (Say)

The possible involvement of the osphradium of Biomphalaria glabrata (Say) in food finding has been investigated by using behavioural assays to determine whether snails with cauterized osphradial canals can locate a source of food extract in still water. A new technique for anaesthetizing the snails for the cautery experiments is described. The experimental results indicate that a functional osphradium is not essential for directional movement towards a source of food extract. The present results are in conflict with those of Michelson (1960). Reasons for the differences between the present results and those of Michelson and the possible functional roles of the osphradium are discussed.     

果蝇产卵行为的偏好和可塑性实验模型

我们用经典的Sherrington模型构建了一个以食物环境为输入,果蝇产卵行为为输出的神经行为学模型,并且对这个模型的敏感性以及可塑性进行了探索性研究．通过给果蝇提供不同的食物成分和浓度,我们发现,果蝇在不同浓度的食物上产卵量有明显偏好差异,并表现出很好的敏感性和稳定性．而当阻断了果蝇的嗅觉感受神经元后,产卵的浓度偏好受到了影响．另一方面,我们用经典条件化的学习方式对果蝇的产卵行为进行训练后,发现果蝇也可以学会将光照条件和产卵行为偶联起来．这也证明了这个模型具有很好的可塑性．这个模型将为今后进一步研究果蝇食物偏好、产卵行为、条件化学习等的神经和分子机制奠定良好的基础．     

In vivo recordings of neuroendocrine cells (caudo-dorsal cells) in the pond snail

Summary Ovulation and egg-laying behavior in the pond snailLymnaea stagnalis are controlled by the neuroendocrine caudodorsal cells (CDCs), constituting two clusters — one in each cerebral ganglion — totaling about 100 cells. In vitro studies have shown that the CDCs release their products, including the ovulation hormone, during a burst of spiking activity lasting for about 30 min (CDC discharge). This burst can be initiated by repeated intracellular stimulation with depolarizing current pulses, in which case the firing pattern is termed afterdischarge.Using cuff electrodes we recorded extracellularly from the intercerebral commissure, (the neurohaemal area of the CDCs) to study the activity of these cells during spontaneous egg-laying of freely behaving snails.The cuff-implanted snails showed long-lasting spiking activity prior to every bout of egg-laying. These spontaneous long-lasting discharges had several features in common with the intracellularly recorded activity of the CDCs in vitro: the time courses of spike broadening and of firing rates in the cuff-implanted animals were very similar to the characteristic patterns found in the isolated brain. Firing rates were higher and durations were longer in the cuff-implanted animals, however. In vitro, the duration of the discharge could be prolonged appreciably by recording in blood instead of normal saline, indicating that the bathing fluid normally used causes shortening of the CDC discharge. The way in which CDC discharges are triggered is discussed as a possible explanation for the differences in firing rates.The pattern of locomotion during spontaneous egg-laying was largely similar in cuff-implanted and unoperated animals. The level of locomotion was lower in the experimental animals. In addition, the rate of locomotion only partially returned to pre-oviposition levels. This is ascribed to the effect of the operation.It is concluded that the afterdischarge is the natural firing pattern of the caudodorsal cells ofLymnaea, and that this firing pattern constitutes the central event in the egg-laying behavior of this animal.Abbreviations CDC caudodorsal cells - CDCH caudodorsal cell hormone - CDCA caudodorsal cell autotransmitter     

Immunolabeled neuroactive substances in the osphradium of the pond snail Lymnaea stagnalis

The osphradium of molluscs is assumed to be a sensory organ. The present investigation in Lymnaea stagnalis has established two ultrastructurally different types of dendrites in the sensory epithelium. Cells immunoreactive to leucine-enkephalin and FMRFamide send processes to the sensory epithelium. These neurons of the osphradial ganglion are thus considered to be part of the sensory system, as are methionine-enkephalin-immunoreactive cells in the mantle wall in the vicinity of the osphradium. The complexity of the osphradial ganglion is further demonstrated by serotonin-immunoreactive neurons innervating the muscular coat around the osphradial canal and methionine-enkephalin-immunoreactive cells sending projections to the central nervous system.     

Effects of diurnal and bidiurnal photoperiodic treatments on mitosis in Pharbitis

Abstract

Photoperiodic effect on mitotic activity of buds from dwarf Pharbitis has been analyzed. No significant differences in mitotic activity were found in plants grown under long days or diurnal (24 h) light break photoperiodic treatments. Differences in both mitotic activity and flowering were seen in plants subjected to diurnal short days, bidiurnal (48 h) short days, or bidiurnal short days with light breaks. An elevation of mitotic activity occurs in plants grown in bidiurnal photoperiodic treatments compared to diurnal treatments. The differences in mitotic activity of buds, both vegetative and floral, seem to indicate that both phytochrome and light effect on an endogenous rhythm influence meristematic activity. Also, the extended dark period of a bidiurnal short day enhances both mitosis and flowering.